Astronomical Sector illustration

Astronomical Sector illustration

C017/3487 Rights Managed

Request low-res file

530 pixels on longest edge, unwatermarked

Request/Download high-res file

Uncompressed file size: 79.1MB

Downloadable file size: 6.0MB

Price image Pricing

Please login to use the price calculator


Credit: DAVID PARKER/SCIENCE PHOTO LIBRARY

Caption: Plate from 18th century encyclopedia showing an illustration of an astronomical sector. The sector, also known as a proportional compass or military compass, was a major calculating instrument in use from the end of the sixteenth century until the nineteenth century. It is an instrument consisting of two rulers of equal length joined by a hinge. A number of scales are inscribed upon the instrument which facilitate various mathematical calculations. It was used for solving problems in proportion, trigonometry, multiplication and division, and for various functions, such as squares and cube roots. Its several scales permitted easy and direct solutions of problems in gunnery, surveying and navigation. The sector derives its name from the fourth proposition of the sixth book of Euclid, where it is demonstrated that similar triangles have their like sides proportional. .

Release details: Model release not required. Property release not required.

Keywords: astronomical, astronomy, brass, compass, cube-root, encyclopedia, euclid, gunnery, illustration, instrument, mathematical, mathematics, navigation, proportional compass, ruler, scales, sector, square, surveying, triangle, trigonometry

Licence fees: A licence fee will be charged for any media (low or high resolution) used in your project.